1. Field of the Invention
The invention relates to a cooled piston for internal combustion engines with a separate piston head and piston skirt. More particularly, it relates to a steel or iron piston head joined to the piston skirt by means of the piston pin. The underside of the piston head is provided with bores.
2. Summary of the Invention
It is an object of the present invention to provide a piston which has improved heat transfer from the piston head and ring belt to the engine block.
These and other related objects are attained according to the invention by a piston for internal combustion engines with a separate piston head and piston skirt. The steel or iron head is joined to the skirt by means of the piston pin. A ring belt, into which the ring grooves are set, projects downward from the head and terminates above the pin. The ring belt defines an outer border of a cooling oil ring space. The inner border of the ring space is defined by a section of the head which is an extension of the piston base. This section is located over two hubs which form a mount for the pin. A depression is formed in the head and base and is partly defined by the section.
In the area of the cooling oil ring space, bores are provided which extend upward toward the top of the head. Advantageously, the bores increase the surface area of the underside of the head and allow more efficient cooling .